The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

Limit office party drinks, experts warn

It may be wise to rethink that extra drink at the office Christmas party.

As employees prepare to attend end-of-year celebrations, drug and alcohol experts warn that too much alcohol can seriously inhibit an individual's decision-making ability.

Professor Dan Lubman, director of Melbourne's Turning Point Alcohol and Drug Centre, said people who drink excessively could find themselves making risky choices they later regret.

He said the decision-making part of the brain becomes less effective as more alcohol is consumed.

"That means we are more likely to do things which we would not normally consider, which explains the increased rates of road accidents, injuries and assaults associated with intoxication," Prof Lubman said in a statement.

"Women under the influence of alcohol are also more likely to be sexually assaulted."